Frequency bands associated with various protocols are specified per industry standards for cell phone and mobile device applications, WiFi applications, WiMax applications and other wireless communication applications. As new generations of wireless communication devices become smaller and packed with more multiband functions, designing new types of antennas and associated air interface circuits is becoming increasingly important. In particular, a communication device with an air interface tends to be affected by use conditions such as the presence of a human hand, a head, a metal object or other interference-causing objects placed in the vicinity of an antenna, resulting in impedance mismatch and frequency shift at the antenna terminal. Accordingly, an impedance matching solution is required in the device to optimize the performance by adjusting impedances over multiple bands as well as according to use conditions and environment while using as little real estate as possible.